root { 
    display: block;
}

body {
    font-family: Calibri, Arial, Tahoma, Verdana; 
    margin:50px 0px; padding:0px;
    text-align:center;
}

th {
    background-color: #b0b0b0;
    text-align: center;
}
form td {
    background-color: #b0b0b0;
}

tr.odd td  {
    background-color: #f0f0f0;
}

tr.even td  {
    background-color: #d0d0d0;
}

.error {
    border: solid 1px red; 
    background-color: gold; 
    padding: 10px
}
div {
    border: dotted 1px greenyellow;
    background-color: azure;
    width: 50%;
    padding: 10px;
    margin-right: auto;
    margin-left: auto;
}
a{
    text-decoration: none;
}
.button{
    padding: 2px;
    margin: auto;
    background-color: buttonface;
    border: solid 1px black;
}